I don't think it will affect the franchise at all. Like others have said, I think X & Y being released on the 3DS would increase sales. Seeing as I don't think Nintendo is releasing games for the DS anymore, I think many will move on and even be motivated to buy a 3DS because of the release of these new games. Although the 3DS is quite expensive, people need to realize that if they want to continue playing Nintendo games, they're going to have to move on to the 3DS and more enhanced systems eventually.